用于三电平脉宽调制整流器中的虚拟磁链

Virtual flux in a three-level pulse width modulation rectifier

为实现无传感器控制,提高系统可靠性和降低成本,研发了三电平脉宽调制整流器中虚拟磁链的观测方法,给出基于虚拟磁链的三电平脉宽调制整流器无网侧电压传感器控制的两种典型应用。分析了应用虚拟磁链后系统启动容易出现过大的电流浪涌问题,提出虚拟磁链预计算和软启动控制策略。实验结果表明,该方法能够实现三电平脉宽调制整流器的无网侧电压传感器控制,并能降低系统启动电流约50%。

Sensorless control gives higher reliability and economic benefits. This paper describes a method to calculate the virtual flux for a three-level pulse width modulation （PWM） rectifier. Then, two control strategies are given for a three-level pulse width modulation rectifier without power source sensors based on the virtual flux. Pre-calculation of the virtual flux and a soft-startup control scheme were used to reduce excessive surge currents during system startup. Experimental results show that the scheme can be easily applied to control a three-level pulse width modulation rectifier without power source voltage sensors, and that the startup current is reduced about 50% by the soft-start process.